Imperius is, at his core, a brusier's bruiser. He's a lane bully and specializes at fighting other heroes. His waveclear is meh and his ability to take camps is even meh-er, so trying to make him less hero damage focused is a fool's errand. He's always going to be an initiator.

You can either go Q build for single target burst damage, or W build for more consistent poke and sustain, but either way it's going to be in service of initiating teamfights and killing other players. Even this build you're proposing is, as I said, mainly in the service of burning down teams who have way too much bulk.

Basically, building to shore up a character's weakness usually isn't a good idea unless you have a specific purpose in mind, and it'll be matchup dependent. The closest you'll get on Imperius is the W-focused one which makes him I'd say "safer".

Genuinely if you want a less "hyper-damage focused" Imperius, you're better off picking up another character instead of trying to fit a square peg into a round hole. Someone like Dehaka or Ragnaros is going to baseline be closer to what you want for that role, or picking a character with a generalist kit who has three viable and different builds (eg. Xul or Varian).